Disparate but Connected

The photographer Wolfgang Tillmans has long been occupied with what he has called the “objectness” of a photograph, its role as a thing in the world and not just as “a conduit of information,” and this has often led to explorations of the relationship between painting and photography in the digital age. A tightly focused exhibition opening Tuesday at the Philadelphia Museum of Art takes Mr. Tillmans’s fascinations and runs with them.

The show “In Dialogue: Wolfgang Tillmans” puts one of his recent, imposingly large photos, “Night Still Life,” together with a group of disparate works by other artists, like a retouched snapshot by Gerhard Richter; a crumpled-paper “sculpture” designed by Marcel Duchamp; and a checkerboard-painted human skull by Gabriel Orozco. The pieces play with the blurry distinction between two and three dimensions that has always existed in art but grew pronounced in the image-saturated late 20th century. (Through Oct. 26, Perelman Building, 2525 Pennsylvania Avenue, 215-763-8100, philamuseum.org.)